Mold for making ship hulls and like floatable structures



July 3, 1923;.

E. A. LARSEN MOLD FOR MAKING SHIP HULLS AND LIKE FLOATABLEJ STRUCTURES Original Filed June 50 I/VI/E VTOF.

Patented July 3, 1923.

: stares 1 EDWARDA. LAR'sEN, or, Lnnksrunclenrronnm.

' Morn ron MAKING SHIP HULLS ANn'jLIKE 'n oA'rABLn 'sreuorun'nsi ApplicationfileduJ'une so, 1921, Serial No, 4s1,5ss;' Renewed my 14, 1923;

To all whom it may concern I Be it known that I, EDWARD AQTIJABSEN,IQ a resident of Larkspur, in the county of Marin and State of California, have invented new and useful Improvements in Molds for Making Ship Hulls and like Floatable Structures, of which the following is a specification. i

This invention forming bodies of. cementitious materials,

andiis particularly useful for forming ship.

hulls, and like floatable structures of plastic material.

The principal object of my invention is to provide a mold whichcan be permanently. used, time and again, in the successive mold ing of ship hulls in quantity production and with speed-and economy.

The important feature .of-myinvention is,

that the mold is built in an enclosed basin or' drydock' in which water, under control of valves or a seagate, may befeitherintro duced or excluded at will, and by such introduction ofi:water, cause the mold. to be automaticallydismembered and floated, so as to let free, when formed, the cast hull',tand permit floatation'thereof, and, conversely,

by. removal of the water from the basin,

causev the reass'embling of the mold to its original molding form.

' To accomplish this object the mold is preferably built so that thetidal'waters' may, under control, enter or exit, to or fromthe mold. The mold is made in sections adapted to 'becomebuoyant and float immersed in the introduced water, and, while so floating and rising, as the water level raises, to be also drawn angularly sidewise awayfrom the center of the mold, the sections being so drawn angularly up an inclined resultant line (on a guide track) formed by the com- "bined vertical floating action and horizontal transverse action-'-and conversely, by allowing the waters to recede in the basin, the sections by virtue of the lowering of the water level orby their gravity will assemble again to molding form. Thus .it will be'seen'that, varying the water level varies the positions of the constituted parts of the mold.

From the foregoing it will be'clear that the salient featureof:my invention is the relates to a device for that is, the operation of the mold, by succes fQ 7 i sive introduction and discharge of water. I

When the water excludedifrom th basi and the mold is assembled,-'work begins and I thehull is cast, and," whenthe'avatersiare introduced into vathe basinithe mold is ,d' membered and the hull is floated.

The engaging faces of the mold sections 5 at the jointsmaybe angular-to eachother,

Qlltal andverticalcross sectionf I i .so that, the'mold sections,r g b1 t r stones or'voussoirs of anfarch. The vertical planes of the sections Y which" engage at the joints being angular to each i other, admit-of the withdrawal of'the sections separately or collectively without coi1--' tacting one another vand further, certain s ece tions of themold=may be made so as to adjoining sections, this means permitting the, i

mold sections 'to move uniformly'vwithout contact and to operate much easierthanif' 1 the members were of'rectangular' shape, as r no sticking or'bi'nding'is possible;

tension, sidewisex-by cables 'conn'ectedTto' ratchet or brake'to hold? the members in disassembled form .while "the basin is" free of i water. The molding walls have openings through them of a sieve character and are firstcoat l '1 ed with a solublev compound andthen rwith awaterproof lining to holdthe lwet cement material forming. the i'hull from-leaking out of the' mold and wheri"the hull is ito bewt I floated the'soluble compound dissolves-by contact with the water-and forms a-sli'p'peryf 5 3 lubricant and the waterprooflining floats with the hull and adheres thereto; The bot? tomv of the'mold isfintegral with the-dock" andis made hollow so as tohold water to dissolve: thejfcompound. Y l

Referring to the several figures:

F ig. 1, shows a plan of the drydock w1th mold therein for molding ship hulls.

Fig. 2, shows a transverse section through mold and drydock.

Fig. 3', shows a detail sectio hrough the molding walls of the mold showing the sievelike character and the holding reservoir back of same.

Fig. 4:, shows a section of the guiding tracks for the travel of the mold sections up.

and down on the inclined surface of mold.

Referring to. the. drawing in which similar numerals refer to similar parts throughout the figures:

Numeral 1. shows the walls enclosing a drydock or --basin below sea level.

2. a seagate opening from the dock to tidal waters.

floatable sections forming the mold.

4:. hull cast in the mold.

5. passage to. float ship out of basinto tidal waters.

6. cables to. assist parts 3 inclinedly up and; away from the cast hull.

7. joints, between sections 3.

8. weights counterbalancing the parts 3.-

9. shows by dotted lines the position of parts 3 and part8 when mold is disassembled;

10. wells permitting weights 8 to rise and fall as mold operates.

11. cellular areas of part 3.

12.'cellular areas of part 3, for. receivingpound 15 onmold walls by passing through the openings 13 in mold walls 20.

20. are the molding walls. .21. water level when the dock contains a body of water.

22. shows a sea valve for controlling. the inlet and outlet of the tidal waters in the basin.

23?.- shows an inlet for injecting or ej ecting a fluid into the cellular areas of parts 3 to a make them heavier than wateror lighter.

24. shows the position of a partly removed key section, which sections when withdrawn perm t the withdrawal of the intervening sections.

The salient features of my invention are; the withdrawal of the molds constituent parts, transversely along and angularly up the inclined slope of the dock and the similar converse assembly of the said parts down the incline slope, the withdrawal of the keystone members, in advance of the counterpart members, in disassembling the mold, and the replacement of the counterpart members in advance of the keystone members in assembling the mold.

The destruction of the adhesive bond of the concrete material (forming the hull) to the mold walls by means of the soluble compound and waterproof lining the sieve character of the mold surfaces. to introduce water between the hull and mold wall surfaces and the preferable placing of the mold in a position below the level of tidal waters or. in a graving dock or in an enclosed Water space communicating freely with a stream or harbor by a passage which may be closedby a seagate. Or on a floating submersible clock.

The operation of the mold is as follows:

The mold sections being assembled in molding form and the dock free of the water,

I the mold surfaces are first covered with a soluble compound and then lined with a waterproof material, reinforcement mer nbers (if any) may then be fabricated andthe cementitious material to form the hull applied with a cement gun and then troweledto a finished surface.

Then the hull is sufliciently matured, water, steam or other. agent may be delivered into the cellular areas back of mold walls to dissolve the compound and at the same ti'me the. tidal waters may be allowed to flood the dock separating and floating the mold sec' tions. from the hull and floating the'hull which may be towed tosea through the sea gate. The mold may be made to cast hulls of; smaller sizes and varying tonnage and shape than the original mold produces. This may be done by securing temporarily to the sectional part of the'originalwalls supple.- mentary forms adapted to give shape to the. smaller hulls. In this case the sectional parts forming the original. mold would function as a mechanical means in expanding and contracting the smaller molds. The mold may also produce a hull of a length less than the original mold produces, this can be accomplished. by removing from the mold some of the sectional parts of the mold and crowding the balance of the sectional parts together to form the smaller hull.

It will be understood that while the above description describes the preferred embodiment of my invention variations in many particulars may be made without depart-- ing from. the spirit of my. invention.

For. instance, the mold sections forfo-rm ing the sides of the mold may be light than water, or heavier than water, the .es-

sential requisite being that they be of such weight'as to be withdrawn from their position by the. counterweights as they become immersed as the water level raises and envelops them wholly or partly.-

Or, themold may be built in a river bed or like water basin so as to permit a hull to be molded during the drought of summer and floated from the mold during the flood tides of winter, in which case no dock, enclosures or control of impounded waters would be necessary.

What I claim is;

1. In the combination, including a graving dock and a molding device ofthe kind described therein, comprising a moldmade in floatable sections adapted to be assembled and disassembled by respectively lowering and raising the level-of water in which the mold is immersed and means for causing the said sections to move angularly upward and away from the center of the mold as the water. level is made to raise and conversely means for causing the sections to move downward and toward the center of the mold as the water level is made to recede, i

2. A mold adapted to be brought successively into positions for molding and also for releasing the product of the mold by lowering or raising the water in which the mold is inundated and means for operating the mold in such manner and means for enclosing and controlling the water for. raising or lowering the level of same to accomplish this purpose.

3. A mold consisting of a plurality of floatable sections built in an enclosed basin below sea level and adapted to be brought into and out of molding position by varying the depth of water in the basin, and,

means for controlling the admittance or discharge of such water in the basin .and means for removing the cast hull from the mold and basin. I

4. A mold consisting of a plurality of separable floatable sections and having an inclined track adapted to guide the said floatable sections upward alongthe said inclined track and away from the central position of the mold and conversely. adapted to guide the said floatable sections downward along the said inclined track towards the central positionv of the mold and hydraulic mechanical means to cause the mold to operate in this manner to accomplish the purpose stateda I 5. A graving dock mold of the character described consisting of an assembly of parts adapted to be brought into engagement by lowering the water level in the dock and conversely adapted to be brought out of engagement by raising the water level in the dockv and means for controlling the depth of water in the dock.

6. The combination including a graving dock and a mold of the kind described, constituted of an assembly ofparts adapted 'stantially as described.

EDWARD A. LARSEN. A 7

tobe contracted 'or expanded by the rise and fall of the tide in the dock andmeans to control depth-of'water in the dock, means for applying supplemental temporary forms to the mold sections to form mold within the original mold for casting hulls of smaller and 'varioustypes, shape and tonnage substantially as described for the purpose specified. I 7 I 7. A mold for casting ship hulls or like floatable structuresconsisting of a floor portion for shaping'the bottom-ofthemold product, separable sections approaching a tetragonin shape for shaping the sides of v i the mold product, said separable sections being adapted to'become buoyantwhen in contact with water whereby their withdrawal from themold product may beeffected and the mold product 'floated, means to operate and guide the said separable sections intoand out of molding form as the water level lowers or raises, openings in the mold floor and walls to-introduce water to release the mold product, a soluble compound on the mold surfaces anda waterproof lining covering said soluble compound. I q

" 8. A graving dock in combination with a mold of the'kind described consisting of separable floatable sections of tetragonal shape, the molding surfaces of, which have openings through the wallsthereof, a cel-;-

. lular floor at the bottom of the graving doclrhaving openings permitting water, communication between the cellular area and the mold area'or theifloor, means for con-ftrolling the Water-level 'in the dock and means for exerting a tensional-pull of the W said floatable section to withdraw them from molding position when in contact with the said floatable sections into and out of moldingposition. v

9. In the combination with a floatable sub-[- mersible dry dock, a mold adapted, to be assembled and jdisassembled by varying the water level relative to the keelof the mold and means to cause the, mold to operate as also for forming a .basefor supporting thesaid parts, mea'ns to cause the said parts to move away from the center of the mold as water let into the dock and means to guide they are buoyed up by a body of water inundating the said parts and means to cause the said parts to move toward the center of the mold as the buoyancy of said parts ceases due-to the lowering of the water level of the inundating body .of water sub-j 

